This invention relates to a relief valve for venting excess pressure.
In pressurized systems, such as plumbing systems in high rise buildings having rooftop tanks for maintaining water pressure on upper floors, the introduction of air into the system can create high pressure events which can cause catastrophic failures. For example, when a slug of water is trapped between two air pockets, and a fixture is used letting the downstream pocket of air escape, the slug is accelerated to very high speed by the expanding air behind the slug. When the slug impacts the fixture, damage occurs. An automatic relief valve can prevent catastrophic failure and potential personal injuries or property damage.
It is known to relieve excess pressure in plumbing pipes with a relief valve having a huddle chamber. Such relief valves are bulky and require two operating pressures: the cracking pressure necessary to unseat the valve, and the opening pressure necessary to fully operate the valve.